Pennzoil Platinum....which weight?

**Hurley711** · 04-11-2009, 08:34 AM

Guys I am leaning towards Pennzoil Platinum 5w-30 for my heads/cam TA. Here is the deal on my driving conditions. It is a weekend summertime cruiser, maybe 1-2 days a week. Gonna be driven in 50-95 degree temps, is the 5w-30 right for me? I've seen some guys running the 10w-30 I just want to make the right choice the first time. Thanks

**Poppn** · 04-11-2009, 09:52 AM

Sarge will chime in quickly, but IIRC the 10w-30 has better shearing resistance....don't quote me on that though haha, but that's the reason I switched from the 5w-30 to the 10w-30.

**Hurley711** · 04-11-2009, 01:27 PM

Sarge runs the 10-30 I believe that I read that in one of the threads.........Sarge?

**pjeff7** · 04-11-2009, 01:38 PM

I am almost positive that he will recomend 10-30

**Hurley711** · 04-11-2009, 02:30 PM

Fom reading other places opinions seem to be mixed between the 5 and 10, with the 10 edging in the summer months. I probably wont drive it in the extreme 90+ heat alot, mostly on T-Top off days in thje 60-80 range temp wise. Car also has 82k miles on it, with alot of peeps rec 10w for higher mileage cars. So confusing

**01WS6475hp** · 04-11-2009, 03:29 PM

I have been running 0-40 mobil1. I like it a lot in my head cam ls1. This time I used 5w40 Castrol Syntec autozone had a special 5 qts and a k&n oil filter for 25 bucks. I also did my 8.1 chevy truck with the same stuff. 30 is to thin for my taste.

**01WS6475hp** · 04-11-2009, 03:32 PM

The first number means nothing unless you live in Alaska.

**Sarge** · 04-12-2009, 04:51 AM

Mobil1 0-40 is a 30 weight after about 5 minutes

So the above poster is running a 0-30 in reality. And that is fine.
10-30 oils have less VI and is much more shear stable than a 5-30.

**Hurley711** · 04-12-2009, 04:53 AM

Originally Posted by Sarge

Mobil1 0-40 is a 30 weight after about 5 minutes

So the above poster is running a 0-30 in reality. And that is fine.
10-30 oils have less VI and is much more shear stable than a 5-30.

Sooo, what should I be running for my driving conditions listed in the original post? 10w or 5w? Patman suggested 5w because "5w can do everything that a 10w does in hot weather and be better on startup" True?

**01WS6475hp** · 04-12-2009, 05:12 AM

Originally Posted by Sarge

Mobil1 0-40 is a 30 weight after about 5 minutes

So the above poster is running a 0-30 in reality. And that is fine.
10-30 oils have less VI and is much more shear stable than a 5-30.

Um learn something new each day. Which is a good thing.

**SteveC** · 04-12-2009, 05:15 AM

I live in a warm climate, and use 10W-30 in both my vehicles.

SteveC

**Hurley711** · 04-12-2009, 05:31 AM

Originally Posted by Sarge

Mobil1 0-40 is a 30 weight after about 5 minutes

So the above poster is running a 0-30 in reality. And that is fine.
10-30 oils have less VI and is much more shear stable than a 5-30.

I actually had 3 gallons of Mobil 1 5w-30, and took it back after reading about Pennzoil oil analysis reviews.

**INMY01TA** · 04-12-2009, 03:32 PM

Originally Posted by Hurley711

Patman suggested 5w because "5w can do everything that a 10w does in hot weather and be better on startup" True?

That's what I've always read.

**TempleU_WS6** · 04-12-2009, 09:24 PM

I run PP 5w-30.

Mostly a summer driver but sees some 30* or below temps. Runs great.

**CompSyn** · 04-12-2009, 09:59 PM

Originally Posted by Poppn

Sarge will chime in quickly, but IIRC the 10w-30 has better shearing resistance....don't quote me on that though haha, but that's the reason I switched from the 5w-30 to the 10w-30.

Yes, Sarge is a big fan of 10W-30 grades. He also mentioned this a while back -

Originally Posted by Sarge

I think you must know how multi viscosity oil works to begin with to better understand. Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees (centigrates or 212f) the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot. So as you can see a 10-30 oil is really a 10 weight oil! It is not a 30 weight oil. Now make no mistake about this. The polymers do wear out.....yes they do.....and this causes shearing....in other words you may start out with a 5-30 but after 500 miles you are running a 20 weight. Polymers is where Royal Purple falls on its face. I have had Royal Purple 40 weights test out at a 20 weight after 500 miles. I dont want a 20 weight oil in my Stroker 408 thank you very much and my wear metals agreed with me

Now to make things more complicated them propeller heads at Amsoil go and use much more robust/expensive Esters and dont use polymers so now I have to say the above applies to all oils EXCEPT Amsoil.

CompSyn